Of course it is not quite as cut and dried as that. Planes may have motorway routes in the sky, but at three kilometres wide, the lanes cover a very wide area. What is certain is that today, as any other day, something over 1,000 aircraft will pass over south-west London.
Hounslow is the area most associated with aircraft blight, sitting around Heathrow's perimeter fence. But the expensive, leafy suburbs of Richmond, Kew, Twickenham and Barnes are also seriously affected. If you consider aircraft noise a serious nuisance, this is not the place to live.
But where is? According to the map of Heathrow Noise Preferential Routes, as they are called, almost all of central, north-east and south-east London is free from flightpaths. In reality this does not seem to be the case.
Christian Wolmar, the Independent's transport correspondent, knows this from experience. When he lived in Finsbury Park, safely to the east of the main northern route into Heathrow, he was often disturbed by aircraft noise early in the morning. Now, two miles west in Tufnell Park - theoretically much nearer the flightpath - he has not noticed any problem.
Another colleague in Elephant and Castle is constantly disturbed by aircraft, even though they should be out of earshot so far from the airport. The only way to find out which areas are aircraft-free is to ask people who live there and who are not trying to sell you a house.
If you look at a map of Heathrow flightpaths - which is about as difficult to get hold of as a spy's home phone number - you will see two main curves sweeping north of the airport, three sweeping south and two more going due east.
In reality, those areas to the west of the airport under the flightpath are far less affected than those to the east. This is because landing is a far noisier business than taking off. And both must be done into the wind. For about 70 per cent of the time this means planes take off and land from east to west.
When aircraft take off, they climb very quickly to above 4,000ft, the height at which they are officially deemed not to be noisy and swing out on their route north or south.
When they land, they descend far more slowly, locking on to the computerised landing system at any point in a straight line up to 12 miles east of Heathrow. By the time they come over Barnes and Kew they are all on the same track and low enough to be heard loud and clear.
When the wind comes from the east, it is a great relief to the residents of south-west London, but far noisier for those in Windsor. When the wind is blowing from the north, Ealing is in the firing line.
Mr Boulton is chairman of Hacan, the Heathrow association for the control of aircraft noise. He has lived on the edge of the Royal Botanic Gardens, Kew, for 24 years. It amazes him that so many people still want to move into the area despite the constant drone from above.
'I think a lot of people don't really appreciate the problem, he said. 'It's not until they get here that they start to ask themselves, do I really have to put up with this?
Certainly the noise cannot be said to affect house prices. The worst affected areas are among the most expensive suburbs of London. Even in north London, it is wealthy Hampstead which lies under the flightpath.
Lisa Brown works for Winkworth in Chiswick and lives in Grove Park which is known as being the worst affected part of the district. She said some people had done their homework and specifically stated they did not want to live under the flightpath.
But that did not stop hundreds of others wanting to live in the area because it has nice houses and good schools. She has just sold a three-bedroom Victorian terrace in Grove Park for pounds 185,000. Five bedroom houses fetch anything up to pounds 400,000. In Kew the prices are even higher. The large detached houses near where Mr Boulton lives start at about pounds 600,000.
Barnard Marcus said people were drawn by the amount of green space and the good schools.
'Occasionally you will be talking to someone outside a house when Concorde goes over and they comment on it, but they are in a minority, said one Barnard Marcus agent. 'It's mostly people from out of London who notice it more. People in London are used to traffic and aircraft noise.
The 7,000 members of Hacan may be used to the noise, but they don't like it and they fear it may get worse. Two major threats loom: the creation of a fifth terminal and the building of a third, more northern runway.
If either happens, Mr Boulton fears Heathrow will do away with two practices which make life half-tolerable for residents like him: the runway alternation system which gives mornings or evenings off, and the brief pause between 11.30pm and about 5am to respect the need for sleep.
'We have always regarded these two things as crucial elements of survival, said Mr Boulton. 'If the fifth terminal or the third runway goes ahead, they will be the first casualties.
He might also find his membership increases sharply in areas such as Fulham and Hammersmith, which would suddenly find themselves directly beneath a four-a-minute flightpath.
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